Easy way to check method / field list in Java REPL

It's a hot topic now.

If you want a list of methods / fields in your program in Java, you can easily find it by using Java REPL. Of course, you can write it as a Java program, but use it when you want to check ** easily **.

Method / field list

In the following example, the method / field list of String class is displayed. Please replace it with the class name you want to check.

String class method list


java> String.class.getMethods()

String class method list


java> String.class.getFields()

List of all methods / fields

getmethodsandgetfieldsThe method is a public method/Only fields are displayed. All methods including private etc./If you want to display the field, execute as follows.

List of all methods of String class


java> String.class.getDeclaredMethods()

List of all fields of String class


java> String.class.getDeclaredFields()

List of all methods / fields (processed version)

If you find it difficult to see at this rate, it will be a little longer, but please execute as follows.

List of all methods of String class (processed version)


java> Arrays.asList( String.class.getDeclaredMethods() ).forEach( System.out::println )

List of all fields of String class (processed version)


java> Arrays.asList( String.class.getDeclaredFields() ).forEach( System.out::println )

For classes that are not loaded by default

For classes that are not loaded by default in Java Repl, import them in advance or describe them with the package name included.

List of all methods of Color class (processed version)


java> Arrays.asList( java.awt.Color.class.getDeclaredMethods() ).forEach( System.out::println )

in conclusion

As mentioned above, it was a topic that was delayed by about 5 to 10 years.

reference

Java: How to output a list of names and values of all fields in a class

Field acquisition with Java reflection API

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